A backhoe-loader of the above kind is known from German Offenlegungsschrift 39 32 555, where the corresponding revolving superstructure is combined with a conventional loader at the front of the undercarriage on a mobile excavator. When excavating, the superstructure together with the boom assembly is pivoted rearward so that depending upon the superstructure's angle of rotation, excavation can proceed either in the extension of the longitudinal center axis of the undercarriage or in a lateral offset from it. Moreover excavation on the side is possible. When loading and when traveling on roadways, the superstructure together with the boom resting to the side of the driver cabin remain pivoted forward in the rest position providing the driver cab an unobstructed viewing of the loading bucket since the raised boom and the downward collapsed bucket arm remain sideways outside the field of view. The implement is seated on the mudguard laterally opposite the driver cab.
When in the rest position and pivoted forward, the boom assembly of prior art equipment, causes the implement to project beyond the lateral limits of the vehicle. Because safety regulations demand that during roadway travel no component may project beyond the lateral vehicle limits, substantially wide implements must be removed from the bucket arm and transported separately. This required assembly and dis-assembly of the implement that, even when using quick-disconnect means, is cumbersome and time-consuming. Moreover special care is required to pivot the boom assembly into the rest position, to prevent the implement from hitting the loader structure, and to remain inside the lateral limits of the vehicle.